Field of the Invention
The present invention relates to a height adjusting device for a bicycle seat post and, more particularly, to a height adjusting device that not only provides a novel structure but also requires fewer elements and allows to be processed, repaired, and assembled easily.
Description of the Prior Art
Generally, a prior art height adjustment device of a bicycle seat post includes an inner tube, an outer tube, an up-down adjusting unit, and an up-down controlling unit. Wherein, the inner and outer tubes are inserted to each other. The up-down adjusting unit is positioned inside the inner and outer tubes. One end of the up-down adjusting unit is fastened to the outer tube, and the other end of the up-down adjusting unit is secured to the inner tube so as to direct the inner tube to move up or down. The up-down controlling unit, operated by a user, is used to manage the up-down adjusting unit to work or to stop. The prior art height adjustment devices of the bicycle seat post, as disclosed in Taiwan Patent 104205140 and 099137166 (hereafter, the prior art cases), are used to adjust the height of the bicycle seat post. The oil-flow control elements of the up-down adjusting units of the height adjustment devices disclosed in the prior art cases are arranged within both the inner and outer tubes, such that the prior art cases have the following deficiencies:
1. Inconvenient to Assemble and Repair:
The oil-flow control elements of the prior art up-down adjusting unit are configured inside both the inner and outer tubes, so the prior art up-down adjusting unit will use both space of the inner and outer tubes when working. Consequently, all the elements within the seat post need to be disassembled for repairing or replacing if the components are out of work. Hence, what it causes is not only inconvenient repairing but also inconvenient assembling.
2. Frail Oil-Block Ring:
As disclosed in the prior art cases, the outer side of the axle wears a hollow oil-block ring, and the hollow oil-block ring is secured to the axle after being worn on the axle. The oil flows are blocked by both the outer wall of the oil-block ring and the inner wall of the tube touching each other so as to prevent the oil of the first oil chamber separated by the oil-block ring from flowing into the second oil chamber. When the seat is adjusted down, there is a strong press-down force suddenly exerted on the seat post. Accordingly, the oil-block ring bears the shear stress from the sudden press-down movement, so it is easy to break. Furthermore, the oil-block ring may easily get thinner because the outer wall of the oil-block ring rubs the inner wall of the tube under long-time behavior of the shear-stress. Thus, it is easy to be worn to cause oil leakage problems and even out of work.
3. Higher Cost:
The oil flow control elements of the prior art cases are configured within the space of both the inner and outer tubes, such that the firing pin for pushing the oil-flow valve needs to be prolonged in length. Therefore, it may increase costs of pins. Besides, the prior art cases comprise many assemblies, and those assemblies may accumulate high standard deviation so that high precision of the assemblies is also required. In consequence, it may result in a high cost in assemblies processing.
It is against the background and the drawbacks associated therewith that the present invention has been developed.